Comment by doug-moen

Since this was posted, the source code was changed, and a makefile was added.

The new version requires ARM 64 or Intel 64 with AVX2. It requires clang-13 (clang-14 and later won't work). Gcc doesn't work.

With clang-14, I got build errors. First error: ./a.h:38:30: error: use of unknown builtin ‘__builtin_ia32_pminub256’ [-Wimplicit-function-declaration]

Seems to be related to this LLVM change which removed the above builtin: https://reviews.llvm.org/D117798

When I replaced __builtin_ia32_pminub256 with __builtin_elementwise_min and ditto for max, then it compiles and apparently works.